A photonic crystal is a periodic optical nanostructure having an effect on photons. A user using the photonic crystal externally receives a pump beam to generate a laser beam having a longer wavelength than the pump beam. When an InGaAsP quantum well structure is used as a gain medium, the photonic crystal laser generates a laser beam at a wavelength of about 1550 nm.
An existing strain gauge has been manufactured in such a way to measure resistance variation. An existing strain gauge for measuring resistance variation is limited in measuring range and resolution. Accordingly, there is a need for a strain sensor with improved measuring range and resolution.